Outlook.com wont receive sendmail but gmail does..

Hi,
I'm using echo "My test email being sent from sendmail" | /usr/sbin/sendmail someemail@outlook.com with hosts file:
127.0.0.1 localhost localhost.localdomain mydomainname
The emails reach perfectly fine to gmail accounts (spam) but never reach any outlook.com accounts. Anyone knows what would could be the issue?
I also tried with hosts: 127.0.0.1 targetmoon.localhost mydomainname . Same results.
Appreciate any help :)
Thanks!

I went over the tutorial followed the steps there. Gmail now receive the emails straight to Inbox and not spam but outlook.com still doesnt show any emails. I have 2 outlook.com accounts to confirm just in case.